Removal of catalyst residues from polymers



United States Patent 3,219,647 REMOVAL OF CATALYST RESIDUES FROMPOLYMERS Richard E. Dietz, Bartlesville, Okla, assignor to PhillipsPetroleum Company, a corporation of Delaware N 0 Drawing. Filed Apr. 26,1962, Ser. N 0. 190,263 5 Claims. (Cl. 26093.7)

This invention relates to the removal of the catalyst residues frompolymers.

Various reactions for polymerizing olefins are described in theliterature, and the polymerizations are usually carried out in thepresence of catalysts. One of the problems encountered with polymersprepared by such processes concerns the presence in the polymer ofcatalyst residues, or ash-forming ingredients. The ash content of aproduct refers to the inorganic constituents which are present in thepolymer in unidentified form and which produce ash when the polymer isburned. The presence of these catalyst residues in the polymer adverselyaffects the color and heat stability of the polymer, as well as itselectrical properties.

Various treating methods have been proposed and tried by the prior artfor the removal of such catalyst residues. It has been suggested thatdicarbonyl compounds containing the group such as acetylacetone and thelike, can be employed as treating agents for removal of catalystcontaminants.

However, the reaction of the treating agent with metal halides, whensuch are present in the catalyst, is accompanied by the evolution of ahydrogen halide. This is most usually hydrogen chloride since the metalchlorides are usually employed as catalysts. HCl generation can lead tosignificant operating problems, especially in commercial equipment, inthe nature of potential corrosion of conduits and vessels. Moreover,with certain of the diearbonyl compound type of chelating agents, onlymoderate rates of extraction are obtained when they are used alone tosequester the catalyst residues. Also, it is believed that, at least insome instances, the presence of hydrogen chloride may tend to inhibitthe chelating reaction. The present invention is concerned with a methodfor employing chelating agents in which these dimculties are overcome bythe presence of certain adjuvant materials used therewith. l have foundthat the use of my adjuvant substantially improves the residueextraction rates.

It has further been observed in a continuous operation for treatment ofthe reactor etlluent with certain of the dicarbonyl compound type ofchelating agents alone, that the solid polymer particles have a distincttendency to agglomerate and plug up the treating vessel.

it is an object of the present invention to provide an improved processfor producing polymers of mono-1- olefins containing a low catalystresidue.

Another object of the invention is to provide a process for treatingpolymers in order to remove catalyst residues associated therewith.

A still further object of the invention is to provide a process forpolymerizing mono-l-olefins wherein the polymerization effluentcontaining liquid monomer and solid polymer is treated so as to removecatalyst residues.

A still further object of the invention is to provide a process fortreating a stream containing polymer suspended in a hydrocarbon diluentso as to remove catalyst residues without said removal being inhibitedby undesirable hydrogen halides.

Yet another object of the invention is to prevent the polypropylene toremove catalyst residues.

agglomeration of solid polymer particles on the surfaces of the vesselin which the reactor effluent is treated to remove catalyst residues.

Accordingly, it is an object of this invention to provide a method ofremoving catalyst residues from a polymer wherein a halogen is a part ofthe catalyst complex.

Various other objects and advantages of this invention will becomeapparent to those skilled in the art from the following discussion andappended claims.

Broadly speaking, our invention is applicable to removal of catalystresidues from polymers prepared in the presence of a catalystcom-position having at least one halogen atom attached to a metal atom.

In accordance with this invention, the foregoing objects are attained bythe use of a combination of a treating agent comprising a dicarbonylcompound with an alkylene oxide having from 2 to 8 carbon atoms, theoxide acting as an adjuvant, or assistant, for the dicarbonyl chelator.In many instances, the amount of chelating agent necessary to reducecatalyst residues to acceptable levels can be reduced, thus the adjuvantoperates to enhance the effectiveness of the chelating agent, in oneaspect by acting as a scavenger for the hydrogen halides liberated fromreaction of catalyst with the chelating agents.

As mentioned hereinbefore, the polymers which are treated in accordancewith the present process are prepared from l-olefins and/or conjugateddiolefins. The present invention is particularly applicable to thetreatment of polymers which are prepared by polymerizing l-olefinscontaining from 2 to 20 carbon atoms. EX- amples of such monomersinclude ethylene, propylene, 1-butene, l-pentene, 3-methyl-1-butene,l-hexene, 1-heptene, l-octene, 4-methyl-1-pentene, 3-methyl-l-hexene,1,3-butadiene, isoprene, 2,3-dimethyl butadiene, Z-methoxybutadiene,l-eicosene, 4-ethyl-l-octadecene, 6-methyl-l-dodecene, 1,3-eicosadiene,4,6-dietl1yl-1.,3-decadiene, 4,5-dimethyl-1-cotene, l-hexadecene and thelike. This invention is particularly applicable to the treatment of Itis to be understood that mixtures of two or more monomers can beemployed in the polymerization to produce copolymers which are thentreated by the present process. Examples of such copolymers includeethylene-propylene and ethylene-butene-l.

This invention is applicable to the treatment of polymers prepared bythe use of catalyst compositions comprising at least one componenthaving at least one halogen atom attached to a metal atom. Such catalystcompositions often include two or more components, one of which is acompound of a metal selected from Groups IV, V, VI and VIII of thePeriodic Table according to Mendeleev, the second component beingselected from organometal compounds, metal hydrides, and metals ofGroups I, II and III of the Periodic Table. Numerous examples of thesecatalyst compositions are well known in the art.

Examples of the second-mentioned component which can be employed includetrimethylaluminum, triethylaluminum, triisobutylaluminum,tri-n-butylaluminum, trin-pentylaluminum, triisooctylaluminum,tri-n-dodecylaluminum, triphenylaluminum, triethylgallium,triphenylgallium, tricyclohexylgallium, tri-n-butylindium,triethylthallium, diethylaluminum hydride, methylaluminum dichloride,dimethylaluminum chloride, ethylaluminum dichloride, diethylaluminumchloride, di-n-butylaluminum bromide, isooctylaluminum diiodide,di-n-propylgallium fluoride, eicosylgallium dibromide,ditetradecylgallium fluoride, dicyclohexylgallium chloride,diphenylgallium bromide, diphenylindium chloride, dioctylindiumfluoride, cyclohexylindium dibromide, 3-methylcyclohexylaluminumdichloride, 2-cyclohexylethylgallium dichloride, ptolylberyllium iodide,di(3-phenyl-l-methylpropyl)indium fluoride,2-(3-isopropylcyclohexyl)ethylthallium dibromide, and the like.

The metal hydrides can include, as specific examples, aluminum hydride,lithium aluminum hydride, barium hydride, gallium hydride, indiumhydride, sodium aluminum hydride, potassium beryllium hydride.

The metals of the first, second and third groups are applicable as aclass, the most important members being sodium, magnesium and aluminum.

The compounds of a metal of Groups IV, V, VI and VIII of the PeriodicSystem include the oxides, hydrides, halides, oxyhalides and salts oforganic acids, usually having twenty or less carbon atoms, such asformic acid, of the said groups of metals, such as titanium, zirconium,chromium, thorium, molybdenum and vanadium.

The alcoholates of a metal of Group IV of the Periodic System which canbe employed conform to the formula X M(OR) where m+n equals the valenceof the metal M, X is a halogen, and R is an organic radical usuallyhaving twenty or less carbon atoms, and preferably being an alkyl,cycloalkyl or aryl group. Specific examples of such alcoholates aretitanium butoxide (tetra-n-butyl titanate), tetra-sec-butyl titanate,tetraisopropyl titanate, tetra-Z-ethylbutyl titanate, tetra-Z-ethylhexyltitanate, tetrastearyl titanate, tetraethyl titanate,tetra(chloroethyl)- titanate, tetra-m-tolyl titanate, tetraallyltitanate, tetracyclohexenyl titanate, tetracyclopentyl titanate,tetraethyl zirconate, tetramethyl zirconate, tetraisopropyl zirconate,tetraamyl zirconate, dichloro diethyl titanate monochloro-triethyltitanate (ClTi(OC H and the dichloro-diethyl zirconate (Cl Zr(OC H Alsoincluded are such compounds as Hf(OCH Th(OC3H7)4,

A third catalyst component which can be used advantageously is anorganic halide or metal halide where the organic radical has thirty orless carbon atoms, and is advantageously an alkyl, cycloalkyl or arylgroup. Specific examples are ethyl bromide, ethyl trichloro titanium,l-bromobenzene, cyclohexyl chloride. Also applicable are an alkali metalor ammonium halide, an aluminum halide (where the catalyst also includesanother metal compound such as a titanium compound), a halogen, ahydrogen halide, a complex hydride, a mixture of an organic halide and ametal, and Grignard reagent.

A still more specific subgroup of catalysts where excellent color andlow ash content are obtained by the practice of the invention includecatalysts where an organometal compound is used in combination with ametal salt. The ratios of the catalyst compounds can vary widely,depending upon the particular charge used and operating conditions, sayfrom 0.02 to 50 mols of the first component per mol of the secondcatalyst component. If a third com ponent is present, the amount canvary from 0.02 to 50 mols per mol of the second component.

Examples of suitable catalyst systems in accordance with the foregoingdisclosure are as follows:

(a) Aluminum trialkyls, e.g., triethylaluminum or triisobutylaluminumand the tetravalent metal halides of the type represented by titaniumtetrachloride;

(b) An organic halide (such as ethyl bromide), a Group IV inorganichalide (such as titanium tetrachloride), and a low valence metalselected from the group consisting of alkali metals, beryllium,magnesium, zinc, cadmium, mercury, aluminum, gallium, indium andthallium, for example, magnesium, ethyl bromide and titaniumtetrachloride, as such, or with the addition of metallic alummum;

(c) A Group IV halide, for example, titanium tetrachloride, and a lowvalence metal identified in (b), for example, sodium or magnesium;

(d) A mixture of titanium hydride and an aluminum alkyl halide, i.e., amixture of titanium hydride and ethylaluminum sesquichloride;

(e) An organoaluminum halide such as diethylaluminum chloride and atrivalent metal halide such as titanium trichloride.

(f) A mixture of molybdenum pentachloride and organometal compounds andhalides exemplified by triethylaluminum and ethylaluminum dichloride;

(g) A mixture of complex metal halides, exemplified by potassiumfluotitanate, and an organometal compound and halides exemplified bytriethylaluminum and diethylaluminum chloride;

(h) A mixture of a derivative selected from the oxides of molybdenum,alkali metal and ammonium molybdates, and an organometal halideexemplified by isobutylaluminum dichloride;

(i) A mixture of a derivative of iridium, platinum and osmium selectedfrom the group consisting of halides, oxides and complex compounds ofiridium, platinum and osmium, said complex compounds corresponding tothe formula M MX wherein M is an alkali metal or an ammonium radical, Mis iridium, platinum or osmium, X is a halogen, and y is at least 1 andthe sum of x and y is equal to the valence of M and a metallic organiccompound exemplified by triethylaluminum, for example, iridium chlorideand triethylaluminum or ethylaluminum sesquichloride;

(j) A mixture of a derivative of a metal selected from the groupconsisting of halides, oxyhalides, hydroxyhalides, oxyhydroxyhalides ofa metal selected from the group consisting of molybdenum, tungsten,uranium, selenium, tellurium, and polonium, and complex salts of saidhalides and said oxyhalides with a member selected from the groupconsisting of halides of sodium, potassium, lithium, rubidium, cesiumand ammonia and an organometal compound exemplified by triethylaluminum,for example, molybdenum pentachloride and ethylaluminum dichloride;

(k) A chromyl halide and at least one of the following (1) a metalhydride or an organometal compound, (2) an organometal halide and (3) amixture of an organic halide and a metal, for example, chromyl chloride,ethyl bromide and magnesium;

(1) (=1) A titanium derivative, (2) a complex hydride, and (3) a halideof aluminum, for example, tetrabutyl titanate, lithium aluminum hydrideand aluminum chloride;

(m) At least one halide of titanium, zirconium or hafnium and at leastone hydride of lithium, sodium, potassium, rubidium, cesium, magnesium,calcium, strontium, barium, lanthanum or thorium, for example, zirconiumtetrachloride and calcium hydride;

(n) (1) A hydrocarbon derivative of one of the metals, zinc, cadmium,mercury, and magnesium and (2) a member selected from the groupconsisting of halides of titanium, zirconium, vanadium and molybdenum,oxyhalides of titanium, zirconium, vanadium, molybdenum and chromium,and complex salts of said halides and oxyhalides with a number selectedfrom the group consisting of halides of the alkali metals and ammonia,for example, diethylzinc and titanium tetrachloride;

(0) (1) A trior tetrahalide of titanium, zirconium, hafnium andgermanium, (2) an organophosphorus-containing compound and (3) at leastone of the following (a) an organo metal halide, (b) a mixture of anorganic halide and a metal, and (c) a complex hydride, for example,triethylaluminum, titanium tetrachloride and a triphenyl phosphine;

(p) (l) A trior tetrahalide of titanium, zirconium, hafnium andgermanium, (2) a peroxide of the formula ROOR' where R is hydrogen,alkyl, aralkyl, alkaryl, cycloalkyl, acyl, alkyne, or aryl, and (3) atleast one of the following: (a) an organometal halide, (b) a mixture ofan organic halide and a metal and (c) a complex hydride, for example,ethylaluminum sesquichloride, titanium tetrachloride and benzoylperoxide;

(q) (1) A trior tetrahalide of titanium, zirconium, hafnium andgermanium, (2) a metal alkoxide and (3) at least one of the following:(a) an organometal halide, (b) a mixture of an organic halide and ametal, and (c) a complex hydride, for example, ethylaluminum sesquichldride, aluminum ethylate and titanium tetrachloride;

(r) (l) A halide of titanium, zirconium, hafnium or germanium, (2) ahydride selected from the group consisting of hydrides of aluminum,gallium, indium and thallium and complexes of said hydrides with alkalimetal hydrides, and (3) an organic halide, for example, titaniumtetrachloride, lithium aluminum hydride and ethyl bromidc;

'(s) (1) A halide of titanium, zirconium, hafnium, or germanium, (2)carbides and acetylenic compounds and (3) at least one of the following:'(a) an organometal halide, (b) a mixture of an organic halide and afree metal, and (c) a complex hydride, for example, ethylaluminumsesquichloride, titanium tetrachloride and copper acetylide.

One catalyst system which is preferred for use in the polymerizationcomprises a dialkylaluminum chloride and titanium trichloride, thelatter compound preferably being prepared by reduction of titaniumtetrachloride with aluminum. The reduction product thus prepared is acomplex having the approximate formula 3TiCl -AlCl The reductionreaction can be carried out at an elevated temperature, for example, ata temperature in the range of 360 to 600 F., preferably from 375 to 450F.

The amount of catalyst employed in the polymerization can vary over arather wide range and will depend at least to a certain degree upon theparticular catalyst system utilized. However, the determination of theactual amount of the catalyst employed in any particular polymerizationis well within the skill of the art. In general, the mol ratio of theorganometal compound to the metal halide falls within the range of 0.02to 50.

Although not essential, it is often desirable to carry out thepolymerization in the presence of elemental hydrogen.

The systems used for removal of catalyst residues by the method of thepresent invention include an alkylene oxide and a dicarbonyl compound.The dicarbonyl compounds used with the adjuvants of this invention arethose materials containing the group:

Such materials are those selected from the group consisting of (:2)compounds of the general formula: 3

and (b) compounds of the general formula:

0 H 0 Rotators In compound (a) each R can be an alkyl, cycloalkyl, aryl,aralkyl, alkaryl, alkylcycloalkyl, or cycloalkyalkyl group or the Rs canbe joined to form a cyclic structure and R can be hydrogen or an alkyl,cycloalkyl, aryl, alkaryl, aralkyl, alkylcycloalkyl, cycloalkylalkylgroup, the number of carbon atoms in each R and R being from 1 to 8.

In compound (b) R" is an alkyl, cycloalkyl, aryl, aralkyl, alkaryl,alkylcycloalkyl, cycloalkylalkyl group or an OR"" group group; R ishydrogen or a hydrocarbon group as defined for R"; and R"" is ahydrocarbon group as defined for R", the number of carbon atoms in R",R', and R"" being from 1 to 8.

Typical of such compounds are 2,4-pentanedione (acetylacetone), 2,4hexenedione, 2,4 heptanedoine, 5- methyl 2,4 hexanedione, 2,4octanedione, 5,5 dimethyl 2,4 hexanedione, 3 ethyl 2,4 pentanedione, 2,2dimethyl 3,5 nonanedione, l cyclohexyl 1,3- butanedi-one, 5,5 dimethyl1,3 cyclohexanedione, 1- phenyl 1,3 butanedione, 1 (4 biphenylyl) 1,3-butanedione, 1 phenyl 1,3 pentanedione, 1 phenyl- 5,5 dimethyl 2,4hexanedione, 1,3 diphenyl 1,3- propanedione, 1,4 diphenyl 1,3butanedione, 1- phenyl 2 benzyl 1,3 butanedione, 1 phenyl 3- benzyl 9,11nonadecanedione, 8,10 heptadecanedione, 8 ethyl 7,9 heptadecanedione, 6octyl 5,7 undecanedione, 4 phenyl 3,5 heptanedione, 1,3cyclohexanedione, ethyl acetoacetate, methyl acetoacetate, n-propylacetoacetate, isopropyl acetoacetate, tertbutyl acetoacetate, diethylmalonate, dimethyl malonate, di-n-propyl malonate, diisopropyl malonate,ditert-butyl malonate, octyl acetoacetate, heptyl acetoacetate, phenylacetoacetate, diphenyl malonate, dicyclohexyl malonate, dicyclohexyloctylmalonate, dihexyl phenylmalonate, ethyl 3-oxopentanoate,octyl-3-oxoundecanoate, methyl 3-oxo-4-phenylbutanoate, ethyl 3-oxo-S-phenylpentanoate, octyl 3-oxo-2-pl1enylundecanoate, octyl3-oxo-2-octylundecanoate, cyclohexyl 3-oxo-6-cyclopentylhexanoate, andthe like.

Of the various compounds represented by these formulas, acetylacetoneand ethyl acetoacetate are preferred.

The alkylene oxides used as adjuvants in the present invention arecompounds containing from 2 to 8 carbon atoms and which include in theirmolecular structure at least one oxirane group having the structureThese compounds can be represented by the general forin which each R andeach R can be a hydrogen atom, an alkyl, cycloalkyl, or aryl group, oran epoxy-containing cyclic or alicyclic hydrocarbon group; and in whichthe R groups can be joined to form a carbocyclic group.

Typical compounds of this type include: epoxyethane, 1,2 epoxypropane,1,2 epoxybutane, 2,3 epoxyb-utane, 1,2,3,4 diepoxybutane, 1,2,4,5diepoxypentane, 1,2,4,5,7,8 triepoxyoctane, 2,3 epoxy 2,3dimethylbutane, 2,3 epoxy 2 methyl 3 ethylpentane, epoxyethylbenzene,epoxyethylcyclohexane, epoxyethyl 3,4- epoxycyclohexane, 1,2epoxycyclohexane, 2,3 epoxyethylcyclohexane, 1,2 epoxycyclopentane, andthe like.

The amount of dicarbonyl compound used will be from 1 to 5 gram mols pergram atom of total metal in the catalyst charged. The amount of alkyleneoxide used Will be sufficient to provide from 1 to 5 gram moles of oxideper gram atom of halogen in the catalyst charged. The chelator .andadjuvant can be introduced directly by themselves into the contact zone,or they can be added separately, or in combination in solution in aninert hydrocarbon.

In the preparation of polymers of monoolefins, a presently preferredprocedure involves conducting the reaction in the presence of a catalystcomprising an alkylaluminum halide and a titanium trihalide, thetemperature being maintained at a level such that the polymer is formedas a finely divided solid. The reaction is conducted in a suitablereaction diluent. While various hydrocarbons can be used as diluents, itis generally preferred that the polymerization be conducted .as a massoperation in which the unreacted monomer acts as the diluent. Bywhatever means the polymerization is conducted conditions are maintainedsuch that the polymer is formed and recovered as a finely divided solid.

' In the preferred practice of the invention the polymer is dispersed insolid state in a hydrocarbon diluent and treated in such dispersion. Inmany instances it is convenient to conduct the polymerization using theliquid While the method of this invention is particularly useful intreating dispersions of solid polymers to remove catalyst residues, itcan also be employed to advantage to treat polymers in solution. In manypolymerization sysmonomer as the reaction diluent under conditions toproterns, the reactor eflluent comprises polymer in solution vide apulverulent solid polymer and treat the olymer in a hydrocarbon solvent.Such a solution can be passed for removal of catalyst in this diluentafter termination to a treating vessel wherein the extracting agent ofthis of the polymerization, However, it is within the scope invention iSadded. The contact time iS fOr a period sumof the invention to replacethe unreacted liquid monomer Ciellt reduce the Catalyst residues in theIeCOVered after polymerization has been terminated with another 10 p yto an acceptable level, which y be from a few hydrocarbon material andconduct the extraction step minutes p Severalhourstherein. In any caseit is important to prevent contact The P y is Separated from the liquidPhase and of the system with air or moisture prior to an during the canhe further P if desired, y Washingextraction step. Extraction will beconducted in a tem- A more Comprehensive understanding of the inventionperature range h h h polymer ill not b d 15 can be obtained by referringto the following illustrative graded and for a sufiicient period of timeto reduce the exh-fhphes which are not intended, however, t0 be undulyundesired impurities to an acceptable level. This time hmltative of theinventionwill vary with temperature, degree of mixing, etc., but AMPL Iwill generally be q one minute to Several hours pref A series of runswas conducted in which propylene was loolmmutes' b d fil h polymerized.Some of these runs were made in a twoi urrly 6 passet a 2 5. gallonreactor, the remainder in a one-gallon reactor.

6 Rate so 1 p0 i IS Separa 6 i 6 1 Hen The reactor charges used areshown in Table I. the latter also containing the catalyst residues. Toremove any adhering liquid, the polymer is washed on the Table I filter,removed and dried.

In a preferred embodiment of the present invention, Mam) a polymerslurry, which has been treated according to the present invention toextract catalyst residues, passes g jggft glf gm 8'3 8% to a washingstep wherein the solid polymer undergoes Hyd rr 15r t I III: 510 310further purification comprising contacting the polymer g ggliggg s 3' 3particles countercurrently with a hydrocarbon which is Time, hoursl 2 2maintained in the liquid phase, preferably the same olea 3T0 MCI finused in the polymerization. Various hydrocarbons, b i chloride,particularly paraflinic hydrocarbons containing from 3 to Based on p pycharged- 7 carbon atoms per molecule, such as pentane, heptane, Thetitanium trichloride complex and diethylaluminum and the like, can beemployed as the wash liquid, although, chloride were charged first,after which the reactor was as stated, it is preferred to utilize themonomer in liquid closed and the hydrogen introduced. The propylene wasphase for this purpose. then charged and the temperature adjusted. Atthe end The treated effluent is removed from the treating to the of thepolymerization in the one-gallon reactor, the diwashing zone for thepurification step just described. carbonyl compound was injected alongwith the desired The overhead stream recovered from the wash zoneconamount of propylene oxide after which the temperature tains monomer,soluble polymers, catalyst residues and was adjusted to extractingrange. After extraction the a small amount of solid polymer. This streamcan be extracting solution (propylene plus chelator and propylseparatedinto its various components if desired and the ene oxide) was drainedliquid phase. The polymer was purified monomer recycled. The bottomstream from then rinsed twice with three liters of propylene. thewashing zone comprises a solid polymer substantially In the two-gallonreactor at the termination of polymfree of catalyst residues. erization,the excess propylene was vented gas phase after The present invention isparticularly applicable to which one gallon of dry heptane was charged.The tempolymers such as polypropylenes, prepared by polymeriperature wasadjusted to extraction level and the dicarzation of propylene in thepresence of a catalyst system bonyl compound and propylene oxidecharged. After comprising a complex of titanium trichloride which canextraction the heptane was pressured from the reactor be represented bythe approximate formula 3TiCl -AlCl through a dip tube and the polymerrinsed twice at room together with diethylaluminum chloride, thepolymerizatemperature with one-gallon portions of dry heptane. In tionbeing carried out at a temperature in the range bethese operationssuitable controls were run and the comtween 100 and 140 F. While notessential, it is freparative catalyst removal obtained. Observationswere quently desirable to conduct the polymerization in the also made tonote the presence or absence of hydrogen presence of elemental hydrogencharged to the reactor chloride from the extraction step. Data aretabulated in prior to or in combination with the monomer charge. TableII.

Table II 1 PROPYLENE OXIDE AS ADJUVANT FOR ETnYL AOETOACETATE FORTREATMENT OF POLYPROPYLENE Extraction Oat. residues, p.p.m.

Run Slurry No. medium EAAB Prop oxide HCl evolution Time, min. Temp, FTi Al Gm Equiv. Gm Equiv n 1 Propylene 90 120 4.16 1.2 240 HCl evolved.2 d0 4.16 1.2 0.996 1.2 50 15 None. 3 d0 30 120 4.16 1.2 0.996 1.2 11320 Do. 4 do 90 4.16 1.2 34s as HClevolved. s do 90 140 4.16 1.2 0. 9961.2 45 12 None. 6 n-Heptane 60 140 4.77 1.1 1. 207 140 HClevolved. 7 d060 140 4.77 1.1 1.133 1.1 77 13 None.

a Ethyl acetoacetate. b Times stoichiometric amount for total T1 and Al.9 Times stoichiometric amount for atoms 01 in catalyst.

This example shows that titanium and aluminum are removed mosteffectively with a combination of ethyl acetoacetate and propyleneoxide, and that the values so obtained are lower than with ethylacetoacetate alone. It is also shown that the evolution of HCl iseliminated when the propylene oxide is present.

EXAMPLE II A run was made in the one-gallon reactor according to theprocedure described in Example 1. Treatment for catalyst removal wasconducted with acetylacetone and propylene oxide. Data on this work areshown in to the chelating agent feed tanks, as desired. The chelatingtreatment took place at a temperature of 140-145 F. under a pressure of400 p.s.i.g. to maintain the unreacted proyplene in the liquid phase.The contact time in the contacting vessel ranged from 45 minutes to onehour. The treated efiiuent was withdrawn from the upper portion of thecontacting vessel and passed into the upper portion of a polymer washcolumn. Washed polypropylene was withdrawn from the lower portion of thewash column and samples taken for analyses.

A chronological log over the course of several days of Table III.continuous operation of this unit, describing observed T able IIIExtraction Cat. residues, ppm.

Run Slurry HCl No. medium Acetylacctone Prop. oxide Ash Evolution Time,min. i Temp, F. Ti Al Gm. Equiv.= Gm. n uim 60 14 5. 8 2. 11 8 34Evolved 60 140 5. 5 0 1 4 1 None.

140 4. 6 2. D l 0 40 D0.

Times stoichiometric amount for total Ti and Al. b Times stoichiomctrieamount ior atoms Cl in catalyst.

When a mixture of acetylacetone and propylene oxide were employed astreating agent for the residues, Ti, Al, and total ash were allsignificantly reduced to within acceptable levels. Moreover, HClevolution was not observed.

EXAMPLE III A continuous run was made in a 50 gallon reactor, for thepreparation of polypropylene. Treatment of the polymer produced forcatalyst removal was conducted with acetylacetone and/or propyleneoxide. The polymerization process was carried out at a temperature about115 F. and pressure of 400 p.s.i.g. The liquid poly propylene feed rateaveraged about 10 gallons per hour. The mole percent of hydrogen in thepropylene feed ranged between 0.14 and 0.19. The aluminum reducedtitanium trichloride complex addition averaged about 0.01 pound perhour. The diethyl aluminum chloride addition averaged about 0.014 poundper hour. The pressure employed in the reactor was sufiicient tomaintain a liquid monomer phase. The residence time for polymerizationaveraged 5 hours.

The reactor efiluent was passed to a contacting vessel whereinacetylacetone as chelator and propylene oxide as an adjuvant were addedin controlled amounts. The acetyiacetone addition averaged 0.074 poundper hour, equivalent to 1.5 times the stoichiometric amount required forcomplexing total metal components of catalyst charged to the reactor.Propylene oxide was charged variations in operating conditions and thequality of the polymer product is listed below:

1st day 0500 hours." The chclating agent feed tank was charged with adilute solution of acctylacctonc in n-pentane. Polypropylene oxide wasomitted, in order to conduct the contacting step with acetylacctoneonly. The acetylacctone was added to the ooutactor at the rate of 0.074lb./hr.

Some plugging was observed in the contacting vessel.

Polymer sample A, weighing 46 pounds, was withdrawn for analysis.Analyzed with an ash content of 218 p.p.m. and titanium of 32 ppm.

The reactor ciiiuent was switched to a flash chamber to bypass thecontacting vessel, as plugging oi the contactor had been very frequent.It was impossible to continue using the contacting vessel and washcolumn system.

Disassembly of the contacting vessel disclosed that the bottom stage ofthe contactor was full of polymer, most of it; being of a fusedconsistency. However, there was a hard ring of polymer around the bottomsection above the agitator blades employed in the contactor.

After the contacting vessel had been restored to service, the reactorefiiuent was directed back to the eontactor and wash column system. Thereactants were soon restored to their normal feed rates to thecontactor.

Polymer sample B, weighing 34 pounds, was withdrawn from the washcolumn. The sample analyzed as 118 ppm. of ash and 31 p.p.m. oftitanium.

Lower stage of the contactor plugged. It was concluded that thecontactor will plug when acetylacctone alone is used as catalyst removalagent. Therefore, the contactor was cleaned and 1000 cc. of propyleneoxide was added to the acetylacct-one present in the feed tank. Thisamount of propylene oxide was equivalent to 1.5 times the stoichiometricamount required to react with the HCl liberated by the reaction betweenacctylaeetone and mctals in the catalyst. Operations were thencontinued.

Polymer sample C, weighing 06 pounds, was withdrawn from the washcolumn. It; analyzed 14 p.p.rn. of ash.

Polymer sample i), weighing 05 pounds was withdrawn. It analyzed 13 ppm.of ash and 10 ppm. of titanium. Operation of the contactor and washcolumn ran smoothly.

Polymer sample E, weighing pounds, was withdrawn. It analyzed 40 ppm. ofash and 12 p.p.m. of titanium.

1105 hours 1630 hours 1640 hours 2nd day 0900 hours.

3rd day" 0400 hours 0830 hours 1330 hours-..

1030 hours."

4th day". 0030 hours 0830 hours It is evident from this run that whenacetylacetone is employed as the sole treating agent, the solid polymerparticles had a distinct tendency to agglomerate and plug up thecontacting vessel. Moreover, catalyst residues in recovered polymerexceeds acceptable levels. Use of the propylene oxide in conjunctionwith the acetylacetone permitted smooth operation of the contactingstep, and reduced the total ash content and titanium content toacceptable levels.

Reasonable variation and modification are possible within the scope ofthe foregoing disclosure and the appended claims to the invention.

I claim:

1. The method of removing impurities from a polymer prepared bycatalytic polymerization in the presence of a catalyst having at leasttwo essential components, one of said components being a metal compoundselected from the group consisting of Group IV, Group V, Group VI, andGroup VIII metal compounds, and another of said components beingselected from the group consisting of organometal compounds, metalhydrides, and metals of Groups I, II and III, and at least one of saidcomponents containing at least one halogen atom attached to a metalatom, which comprises contacting said polymer dispersed in a hydrocarbondiluent, while the latter is under conditions such that said diluentremains in liquid phase, with a treating agent comprising from 1 to 5gram mols per gram atom of total metal in the catalyst of a compoundselected from the group consisting of compounds represented by thefollowing structural formulas:

O H O Retains in which each R can be an alkyl, cycloalkyl, aryl,alkaryl, alkylcycloalkyl, cycloalkylalkyl, aralkyl groups, or can bejoined to form a cyclic structure; R is a hydrogen, an alkyl,cycloalkyl, aryl, alkaryl, alkylcycloalkyl, aralkyl groups; R can be analkyl, cycloalkyl, aryl, alkaryl, aralkyl, alkylcycloalkyl,cycloalkylalkyl, R" can be attached through an O atom; R" is a hydrogenor hydrocarbon group as defined for R; R'" is a hydrocarbon group asdefined for R"; and the number of carbon atoms in each, R, R, R", R andR" being from 1 to 8; and an adjuvant comprising from 1 to 5 gram molsper gram atom of halogen in the catalyst of an alkylene oxide selectedfrom the group consisting of epoxyethane, 1,2- epoxypropane,1,2-epoxybutane, 2,3-epoxybutane, 1,2,3,4- diepoxybutane, 1,2,4,5diepoxypentane, 1,2,4,5,7,8 triepoxyoctane,2,3-epoxy-2,3-dimethylbutane, 2,3-epoxy-2- methyl-3-ethyl-ethylpentane,epoxyethylbenzene, epoxyethylcyclohexane,epoxyethyl-3,4-epoxycyclohexane, 1,2- epoxycyclohexane,2,3-epoxyethylcyclohexane, and 1,2- epoxycyclopentane, and separatingsaid polymer from the resulting mixture substantially free of catalystresidues.

2. Process for the removal of catalyst residues from polymers wherein amono-l-olefin is contacted with a catalyst having at least two essentialcomponents, one of said components being a metal compound selected fromthe group consisting of Group IV, Group V, Group VI, and Group VIIImetal compounds, and another of said components being selected from thegroup consisting of organometal compounds, metal hydrides, and metals ofGroups I, II and III, and at least one of said components containing atleast one halogen atom attached to a metal atom under polymerizationconditions so as to form solid polymer in particle form and wherein anellluent containing solid polymer, catalyst residues, and olefin isrecovered from said polymerization, which comprises introducing saideflluent into a contact zone, mixing said eilluent in said contact zonewith a treating agent comprising from 1 to 5 gram mols per gram atom oftotal metal in the catalyst of a compound selected from the groupconsisting of compounds represented by following formulas:

in which each R can be an alkyl, cycloalkyl, aryl, alkaryl,alkylcycloalkyl, cycloalkylalkyl, aralkyl groups, or can be joined toform a cyclic structure; R is a hydrogen, an alkyl, cycloalkyl, aryl,alkaryl, alkylcycloalkyl, cycloalkylalkyl, aralkyl groups; R" can be analkyl, cycloalkyl, aryl, alkaryl, aralkyl, aikylcycloalkyl,cycloalkylalky, R" can be attached through an O atom; R is a hydrogen orhydrocarbon group as defined for R"; R" is a hydrocarbon group asdefined for R"; and the number of carbon atoms in each R, R, R" R and R"being from 1 to 8; and an adjuvant comprising from 1 to 5 gram mols pergram atom of halogen in the catalyst of an alkylene oxide having fromtwo to eight carbon atoms under conditions such that said olefin remainsin liquid phase; recovering the thus treated efiiuent; washing saidtreated eflluent by contacting same in countercurrent flow with ahydrocarbon having from 3 to 7 carbon atoms under conditions such thatsaid hydrocarbon and said olefin remain in liquid phase; and thereafterrecovering a solid polymer substantially free of catalyst residues.

3. The process according to claim 2 in which said compound isacetylacetone and said adjuvant is selected from the group consisting ofepoxyethane, 1,2-epoxypropane, 1,2-epoxybutane, 2,3-epoxybutane,1,2,3,4-diepoxybutane, 1,2,4,5 diepoxypentane, 1,2,4,5,7,8triepoxyoctane, 2,3- epoxy-2,3-dimethylbutane,2,3-epoxy-2-methyl-3-ethylpentane, epoxyethylbenzene (styrene oxide),epoxyethylcyclohexane, epoxyethyl-3,4-epoxycyclohexane,1,2-epoxycyclohexane, 2,3-epoxyethylcyclohexane and1,2-epoxycyclopentane.

4. The process according to claim 2 in which said compound is ethylacetoacetate and said adjuvant is selected from the group consisting ofepoxyethane, 1,2-epoxypropane, 1,2-epoxybutane, 2,3-epoxybutane,1,2,3,4-diepoxybutane, 1,2,4,5-diepoxypentane,1,2,4,5,7,8-triepoxyoctane, 2,3-epoxy-2,3-dimethylbutane,2,3-epoxy-2-methyl-3-ethylpentane, epoxyethylbenzene (styrene oxide),epoxyethylcyclohexane, epoxyethyl-3,4-epoxycyclohexane1,2-epoxycyclohexane, 2,3-epoxyethylcyclohexane, and1,2-epoxycyclopentane.

5. The process according to claim 2 in which said mono-l-olefin ispropylene and said hydrocarbon is heptane.

References Cited by the Examiner UNITED STATES PATENTS 2,974,132 3/1961Jacobi et a1 260-949 3,002,961 10/1961 Kirschner et al. 26094.93,066,124 11/1962 Telfer 260-93] 3,098,845 7/1963 Cull et al 26094.9

JOSEPH L. SCHOFER, Primary Examiner.

1. THE METHOD OF REMOVING IMPURITIES FROM A POLYMER PREPARED BYCATALYTIC POLYMERIZATIONIN THE PRESENCE OF A CATALYST HAVING AT LEASTTWO ESSENTAIAL COMPONENTS, ONE OF SAID COMPONENTS BEING A METAL COMPOUNDSELECTED FROM THE GROUP CONSISTING OF GROUP IV, GROUPV, GROUP VI, ANDGROUP VIII METAL COMPOUNDS, AND ANOTHER JOF SAID COMPONENTS BEINGSELECTED FROM THE GROUP CONSISTING OF ORGANOMETAL COMPOUNDS, METALHYDRIDES, AND METALS OF GROUPS I, II AND III, AND AT LEAST ONE OF SAIDCOMPONENTS CONTAINING AT LEAST ONE HALOGEN ATOM ATTACHED TO A METALATOM, WHICH COMPRISES CONTACTING SAID POLYMER DISPERSED IN A HYDROCARBONDILUENT, WHILE THE LATTER IS UNDER CONDITIONS SUCH THAT SAID DILUENTREMAINS IN LIQUID PHASE, WITH A TREATING AGENT COMPRISING FROM 1 TO 5GRAM MOLS PER GRAM ATOM OF TOTAL METAL IN THE CATALYST OF A COMPOUNDSELECTED FROM THE GROUP CONSISTING OF COMPOUNDS REPRESENTED BY THEFOLLOWING STRUCTURAL FORMULAS: